This article is a guide to getting your garden into shape and your soil as healthy as it can be. Whether you’ve just moved into a new house or have decided you need to do something more sustainable or just more interesting with your garden, you’ll want to start with the soil, and the first thing you’ll need to do is to find out what you’ve got.
So, start off by testing the soil. We talked about that right at the beginning of the book. Even in quite a small garden, it’s worth testing the soil in different places: walk a “W” and try the soil at each tip and halfway up (or down) each side. A friend did this in a quite small town garden and found one area was incredibly fertile with heaps of organic matter, while another was full of sand and quite depleted. My diagnosis would be that the fertile area had been a rabbit hutch or a chicken coop while the sand might have been left by builders (though it was a big sand heap to go that far down!).
Then decide which area you want to concentrate on. For instance, a large garden might be divided into a wildlife meadow (which will simply be mowed a few times a year) and a kitchen garden, which you’ll make the focus of the first few years’ efforts for improving the soil. If your yard is small enough, on the other hand, you can try to improve all of it before you start growing.
Test the compactness of the soil. If you have very compacted soil, this is the one time that you really should till it, either mechanically or simply by hand digging.
But rather than just digging, use this chance to incorporate lots of organic material and other amendments. It may be worth delaying your planting in order to make the most impact you can on the soil, for instance by incorporating plenty of chipped twigs and fallen leaves, then growing a cover crop, or sheet mulching with cardboard. You may not be able to start growing until a year later, but you will have the immense advantage of starting growing in really good soil.
Add any nutrients that are needed. Even if the soil is good, you can add compost in a 3” layer. Add NPK either by adding an organic fertilizer (e.g., bone meal) or by planting nitrogen-fixing plants.
It’s really good news if you can get started in the fall, as a sheet mulch over the winter will really help to suppress weeds and start improving the soil.
Just before you plant, mix some compost into the soil—just at the top, don’t dig it in deep.
For planting trees and bushes, remember that at this point, plants need help adjusting to their new position and getting settled in, so dig a larger hole than the plant needs. Put some compost in the bottom, water it well, and let the water soak into the ground. At the same time, most trees will need a good root soak, which is easily done in a bucket if you can get the root ball into it. Then plant your specimen, fill in soil around the roots and tamp down well. Water again and mulch well to keep the moisture in and suppress weeds.
One reason for digging a bigger hole than the roots appear to need is that the soil will be nicely broken up so that it’s easy for the roots to grow into the space.
If you’re planting seedlings, simply make sure your soil has been well mixed with compost. I like to grow seedlings in paper or cardboard pots so that I can simply put the pot in the hole without disturbing the roots. The seedling can grow as the pot decomposes. Or, of course, you may be sowing direct, in which case all the work you’ve done on the soil will really help. Remember to water really well when you sow and keep the soil moist while germination occurs and while the plants are young.
Maintenance
Don’t forget that maintaining your garden is as much about maintenance below ground as it is about tidying up what’s above the ground. You need to add new mulch twice a year (in spring, once the ground has warmed up, and in the fall); add compost or water with compost tea. Make sure your crop rotation replaces nitrogen-hungry plants with nitrogen-fixing plants, so your soil doesn’t get depleted (this is one reason you ought to keep good records of what is planted where). Re-test the soil every so often. You may need to add particular amendments.
During the growing season, you will also need to ensure your plants have adequate water. I already talked a bit about water; it’s necessary sometimes, however good your mulching and how good your soil is if you don’t get the right amount of rain for a few days. Even if you use clay pot watering or drip irrigation, you’ll want to stick a finger in the earth in a few places from time to time to check that your plants have the right soil moisture (and not too much!).
Weeding will still be necessary, but if you use mulches, cover crops, and green manures, you’ll have to do a lot less than traditional gardeners. One of the things you’ll develop over time is a good eye for what’s a weed and what’s a seedling or a sucker from one of your plants. Before I learned that, I had a few frustrating experiences exterminating a weed, only to find it was something I’d planted!
Weeding is best done a little at a time. Just going out in the morning and concentrating on a couple of rows and nipping the weeds out before they get a chance to grow is much more effective than spending hours every weekend. Or do your wedding when you get back from work, then take a refreshing shower.
Of course, you can mix above-ground and below-ground maintenance if, when you chop down old plants and do pruning in the fall, you use the waste as a mulch (use a chipper if necessary) or put it in your compost pile. And if you decide to let nettles grow in one patch of the garden, as long as you don’t let them flower, you can chop them down and use them as green mulch or for composting—even weeds can sometimes be useful.
If you grow crops over the winter, you need to think about ‘giving something back.’ All plants take nutrients out of the soil, so if you grow a winter crop like kale, you’ll need to find some way of putting those nutrients back in. You already have all the knowledge you need to make your plan—for instance, you could sow a cover crop or green manure afterward, or add compost—but you do need to make a plan. Good planning is part of maintenance!
Winter maintenance
Most gardens will hibernate with very little growing over winter, so your maintenance is basically about ‘putting the garden to bed.’
At the very minimum, you need to cut down old plants, pull up vines (like tomatoes) by the roots, and tidy the garden. This will avoid disease over the winter. But this isn’t going to add nutrients back to the soil and if you don’t have much mulch left, your soil might be damaged by erosion or too much water evaporates. Chopping the old plants onto the soil adds a little nutrition, but not as much as compost.
So, once you have the garden tidy, it’s worth getting a good barrowful of compost onto your vegetable bed. Rake away any old mulch that hasn’t decomposed and stick it on your compost pile, then mulch with the compost. You might then add more woodchip on top, to suppress weeds or layer cardboard or newspapers over the compost. Alternatively, plant a cover crop rather than leave the soil bare.
Some perennials don’t like their roots to get too cold, so providing a deep straw mulch can help keep the soil warm and keep the plants healthy and ready for next year. I do this with my strawberry and raspberry plants. For raised beds, you might even want to pile straw around the sides to insulate the bed.
Raised Beds And Containers
Of course, so far, we’ve talked about gardens and agriculture where you are sowing directly in the ground. But some people use raised beds for their gardens and of course, there are a lot of container gardeners, some with just a windowsill and a few pots. Their needs are a bit different, so let’s focus on them in this chapter.
Before you make a container garden, you need to know which plants will do well in containers, and which won’t. For instance, sunflowers won’t thrive unless they can put their roots down on real earth. Fig trees, if you buy compact varieties like Brown Turkey, White Marseille, Violette, and Ventura, actually enjoy having their roots constrained, though you’ll need a big container (half a barrel for instance). The same is true for raised beds. If they are open to the soil beneath them—for instance if you’ve put them where there used to be lawn— you can plant anything; if they’re closed—for instance, if you need to put them on concrete hard standing—your choice is more limited. Vegetables with long tap roots like Japanese daikon radishes won’t do well in a closed bed, but you can grow salads, tomatoes, and even carrots.
Find below a table of the root depth of various plants so that you can plan accordingly:
| 12-18 inches | 18-24 inches | 24-36 inches |
| Arugula, Basil, Blackberries, Broccoli, Brussel sprouts, Cabbage, Cauliflower, Celeriac, Celery, Chinese cabbage, Chives, Corn, Endive, Fennel, Garlic, Ginger, Kohlrabi, Leeks, Lettuce, Melons, Onions, Potatoes, Radish, Raspberries, Scallions, Spinach, Strawberries, Zucchini | Beans, Beets, Cantaloupe, Carrots, Chard, Cucumber, Daikon radish, Eggplant, Figs, Jerusalem artichoke, Kale, Peas, Peanuts, Peppers, Potatoes, Squash, Turnips | Artichoke, Asparagus, Okra, Parsnips, Pumpkin, Rhubarb, Sweet potatoes, Tomatoes, and Watermelon. |
A big advantage of using raised beds and containers is that you won’t get soil compaction, as you’re not going to be walking on them; you’ll also get better drainage, which might mean choosing raised beds as a way forward if your ground is very poor-draining clay.
Raised beds
You can buy raised bed structures made of different materials (wood, metal, recycled plastic), or you can easily make your own. Pallet wood (as long as it has not been chemically treated—look for the HT stamp that says it was heat treated instead) is a good, cheap, recycled material, and it’s easy to use the slats for the sides and the bulkier timbers inside for the corner posts. You can even make the sides of a raised bed out of straw bales, though obviously, that bed isn’t going to last very long.
You may need to buy topsoil for your raised beds. Using the topsoil from your garden might work, but you’ll need good-quality soil, which you may not have at home. Buy the highest quality topsoil that you can find; there’s no point starting a raised bed with poor-quality soil. If you get bad soil, you’ll probably also end up with a load of weed seeds, which will make your task much more difficult; make sure the soil has been heating treated or solarized to destroy the weeds.
You’ll also need to buy compost, and again, get the best you can. Peat-free where possible.
Fill the bed with a mixture of about 50% topsoil, 30% compost, and 20% organic materials such as wood chips or cardboard, or grass clippings (a mix is best). You’ll want to mix this up on a tarp, outside the bed, and make sure it’s well combined before you fill the bed. Don’t try to mix it in the bed, as you’ll get an uneven distribution of the components.
In a big raised bed, you can economize by making up a lasagne of shredded leaves, grass clippings, straw, wood chips, and twigs. Fill the bed to about 6” from the top with this mix, then lay cardboard or newspapers on top to stop the soil from falling through and fill the rest of the bed with the soil and compost mix. The organic material will gradually rot down, but there’s already 6” of good soil for your first crops to grow in. When the organic material has completely rotted, you’ll see that the level of soil will fall, so make sure you have plenty of your own compost to replenish the bed with by that point!
Remember that raised beds dry out more quickly than level soil, so add lots of mulch and remember to water frequently.
Container gardening
Your choice of container is important. Different containers vary in insulative qualities, durability, and winter hardiness. For instance, ceramic pots may not make it through a really hard winter, and they also let the water evaporate through the sides. Wooden boxes are lighter than most other kinds of boxes and they insulate well, but they’ll need lining or they will start to rot away in a few years. Plastic pots don’t insulate at all, but they tend to keep moisture in quite well and are light—the smaller ones perhaps too light if your garden is on a balcony or in a windy spot.
The size of a container needs to fit the plant. A miniature apple or fig tree needs a larger pot than salad leaves or tomato plants. You might get a larger pot and plant it with a mix of edible and ornamental plants. ‘Thriller, filler, spiller’ is one way to build a good arrangement: an architectural, tall plant, one to fill up the rest of the pot, and one to trail over the sides. You could also think about making a larger container into a mini-guild or mini-food forest.
Of course, containers also come at different prices, so using old buckets or yogurt containers, or a big old olive oil can from an Italian restaurant with the top cut out, maybe an easier way to get started than buying a lot of terracotta pots.
Just filling your containers with garden soil is unwise. You’ll want to buy a good potting compost and if you mix it with garden soil, make sure the soil contains no weed seeds. You might consider a luxury blend of a third vermiculite or perlite, a third coconut coir, and a third compost. Containers can dry out very quickly and are also prone to compaction; this blend retains moisture better and will resist compaction too compared with a more regular topsoil and compost mix. The mix is too expensive for big raised beds, but if you have pots or a smaller raised bed or two, it might be your best choice.
Next to the soil, the most important factor for container plants is drainage. Put a little gravel or broken tile at the bottom of the pot, and make sure there is a hole in the bottom for the water to drain away. Plants will actually drown if the moisture level gets too high, as there’s no oxygen getting to the roots.
Container plants will need a top dressing of mulch every so often, but they will need all the soil replaced every few years. Do that in the fall, after you’ve harvested, and try not to disturb the root ball too much (if the root ball fills the pot, you need to buy a bigger container).
